Abrading machine



sept-.17, 1957 Filed Jan. 28, 1955 H. AMRHEIN EI'AL ABRADING MACHINE 5 Sheets-Sheet 1 A 77' ORNE Y SSPLU, 1957 H.'AMRHE|N ErAL 2,806,329

ABRADING MACHINE Filed Jan.- 28, l1955 5 Sheets-Sheet 2 H.V AMRHEIN ErAL 2,806,329

Sept. 17, 1957 ABRADING MACHINE 5 Sheets-Sheet 3 Filed Jan. 28, 1955 Heinz AMRHE//V Emf/ LANDECK QL/l@ AToR/vfy Sept.l7, 1957 y H. AMRHEJN lrAL 2,805,329

' ABRADING MACHINE Filed Jn. 28, 1955 5 sheets-sheet 4 /NVEA/raks lle/nz AMRHE/N Emi! LANECK Sept.17, 1957 5 Sheets-Sheet 5 Filed Jan. 28, 1955 M S RH mm NA mm mm. Aia- Ww Q MMV RNWHIIII- LJWI L mw.

W vm Q l u v m c w Wd @i w//V//lim w ,717/17 1 NYM A TTORNEY l 2,806,329 lABRADING' MACHINE `Heinz Amrhein,tBudericl1,.rand `Landeck,.Solingen,

to Fritz WendtQKommanditges'elI- Germany, a manufacturing comeconomy :steel:V castings, "aluminium, bronze,I hard :rubber articles; :'porcelain,l synthetic plasticsretc.

The invention aims-.lat .strengtheningtheiresistance `to wear-.orzfstaying power ofcuttingtoolsi of" the type descr'ibed and'Y at reducing the` hig'h costs t 'of .their` ,production, maintenance iand Vof keeping 1them in/good working order and repair.

In the conventional practice of abrading Vand finishing .cuttngwtools ofthe reinforced typeset forth, an assortment of .rotary abrading discs are mostly used in succession, whichare itted `circumferentially with differently' graded pulverulent diamond'particles.

Asfa .matterzofzfact, observed by the inventors, cutftingxedges oftools thusproduced sometimes appear to be a .saw 'withfirregular serrations, when seen under a large-:rate ofmagniiication of'say about three hundred.

`Thisis certainly due `to the `aforesaid practice, wherein .the` abradingwheels pass over the working faces and across the cuttingfedges of the cutting tool with their abradingz'diamond particles, however small, repeatedly proceeding over the same `points and in the same direction.;

Another cdrawbaclr: involved inithe employment of rotary: abradingwheelsis, that 'over-heating of the surfacesuxof tth'e-i` cutting tool occurs, which .leads to cracks therein"v and tresults .fin-Lthe edgesl breaking prematurely away;

Still anotheridisadvantage inherent to the employment .ofaa-.seriesfoflrotaryabrading Wheels is, that vall together they-ihaveftasveryflargevabrasive surface and, because of'ithe costly fdiamondsettings therein, `are -rather expensive.`

Therinventionffaims: at overcoming all the aforesaid drawbacks.. :In.the1abradingvand finishing machine redesigned: according to this-invention in contradistinction to prior art grinding machines andto essentially rotational grinding and nishing methods, the cutting tool is xedonsatnonrotating support, so as toiuprightly expose the respective plane surface under treatment to a non-rotatingtiabradingf-tool, whichis reciprocated up and down `and isffsimultaneou'sly and veryrapidly oscillated -in horifzontal: direction.'

.Gbodriiinishing land'. -resharpening results Ywere obtained bylusing-San abradingtool 4.in theform of 'a rather small rectangular block, tted with abrasives :at its frontend "upper, side, and beingfreciprocated and oscillated at' frequencies,2wide'ly dilferentfromleach other, namely the horizontal oscillationsfsurpassingat least three times the "vertical ,reciprocations Z'Iwof forms Zof Vconstruction, embodying the invention faresillustratediinhthe accompanying drawingsyby way `of examples, in which- Fig. lsshows, partly inzlongitudinal.section, the first form of construction .offan abradingmmachine, redesigned according tothis invention,

.Fig..`2.isfa.section,taken Vat--right angles to the axis of the motorsand through aneccentricimparting horizontal oscillating movements to-theabradingblock,

nited States l3nt::nit iice Patented. Sept. V1.7, r.1957

Fig.' 3-isa similar' section" through an eccentric ix'nparting up anddownmovements to ther'ntor,

Fig. 4'show`s`.`a means f securing th'efz'ab'radingt` block t ongthejgrindin'g head,

Y Fig.' Sis a side elevation, partly in section of an ab'rading machine of modified design,

Fig. 6 isa rearelevation, partly in section of themachineV shown in Fig; 5,

Fig. 7 is 'a section`throu`ghthe workA table an'dat'the same time a`front 'elevation of'th'e grinding head,Y n

Fig. 8 is a longitudinal section on line in Fig. 7,

Fig. 9 is a sectiontaken Online IX-IX inFig. 5, vertically4 tothe -motor axis.

In. the construction shown in"Fig.:l-th`e motor 11, wherein a'reducti'ong'ear 12 is mounted at one side,v is arrangedon-a basejpltelS; the base plate 13 rests on two supports eachf .Which-consists 'of 'a -hollow column 14 and a part.15,s`lidble-like a pistonin the2hollow co1- umn.

The parts' V"15 which .are also tubular, ,accommodate in their. bore springs 16z`z` and 16b`, which serve for compensating the weight of 'the motor? andofthe -b'aseplate 13, so that'the device hereinafter described, which imparts up andfdown .movements to the motor, .does not-.have to .lift the weight of the motor, but only.v to overcome the forces of inertia.A t

The-driving shaft'17 `which1may rotate at about 1'210 revolutions per minute carries an eccentricf18'which is connected by a connectingrod"191to a pin`20,rmountedon a stationary part of 'the frame; thus the eccentric 18'compels the motor 11 together withi its baseplate to carry out substantially vertical` reciprocatingv movements at a frequency rate of about 140'cycles`perminute.

As ythe forces .exerted by the connecting ,rod.19 are not directed towardsithe gravitational center of the moved system, there is Ia-.tendency Vto tip. the latter in addition to a sliding displacement. This tippingtendencyis however counteractedpnot onlyY bythe parallel .guidingaction of the parts in the hollow columns 14,'. butV also-by the fact,

, that the springs 16a, which are nearer tothe connecting rod 19 have a resiliencyfactoror.spring constant greater than that ofthe spring 16b.more remote-from .the connecting rod 19.

On .the second drivingshaftfZL whichlmay rotateat about 2800revolutions .per minute, A'another eccentric A22 is mountedjths eccentric willimpart horizontally directed oscillating motions at.a` frequency of v2800 cyclesV per minute to the'grindingffhead, which .is guidedinhorizontal directions by two parallel leaf springs .24; as .the springs 24 lareiixed. on .thecbase plate .'13 andparticipate in .its up and 'down..movement,..the.grinding headcarriesgout up and down reciprocating movements namely, reciprocationsper minute, and at the same .timehorizontally directed 4oscillating to` and fro swinging movements namely Aat a. frequency. of. about 12800 oscillationsper minute.

As shown in Fig. 4 the abradingblocklS is fixed lon the front face of the grindinghead 2'3 fin. suchA manner, Ithat it can be clampedbetween-a stationaryjaw 26 and amovablejawl ZT'by tightening ascrew 28; another useful Vfeature consists therein, that 'the abrasivefront zone 29 of thevblock V25-is surrounded on all sides'bynarrow vzones 30 free from abrasives.

An'additional zone'31' containing abrasives maybe provided 'on theupper` side of fthe abrading block, which maybe 'used to advantage in the re-sharpening and finishing 'operation for preliminarily grinding the side rakeof the cuttingtoolfin `-the`positi^on shown at'32, in which case"I the supanddown'reciprocations `of the motor and of the abrading block are cut out and switched oif.' As indicated above, according'to the' invention the 'machine tool is non:ro'tatalnlytired,`J so to'uprightly expose "the respective plane surface under treatment namely in appropriate height and inclination to the abrading tool.

As seen in Figs. 1, 4 and 8, a table 34 is provided to bring the latter accurately into the proper height and inclination to the abrading block 25, so that during the V movements of the latter the abrasive zone 29 is fully utilized; the table 34 is vertically adjustable in a guide 35, the adjustment is eiected by means of la pinion 36 in mesh with a tooth rack 37, and to be turned by a hand wheel 38.

The angular adjustment of the table 34 is effected by turning the table about the axle 39; the table can be fixed in the desired angle of 'inclination by a clamping device shown at 40.

For the purpose of accurately setting the table 34 in the desired grinding angle, a hand or pointer 41is provided, moving over an angle scale 42; a zero mark 44 (Fig. 4) is preferably provided at the side of the abrading block, to indicate, when the middlerof it is in the central position, and on which the edge of the work piece to be abraded can be set by suitably adjusting the table 34.

A pump 46 is provided for feeding lubricant to the work, and is actuated according to this invention by the base plate 13, so that the piston 47 of the pump is moved up and down and will suck the lubricant out of a trough 48 through a pipe 49 and valve 50, and force it through the valve 51 into the pipe 52, wherefrom it flows on to the abrading zone 53.

Figs. and 6 show another preferred form of construction of the redesigned abrading machine, which differs from that shown in Fig. l in the following respects: For effecting the vertical swinging movement of the motor an eccentric 61 is employed which acts on the carrier 63 through the intermediary of a ball bearing 62. This eccentric is again driven by one of the driving shafts through the intermediary of a gear consisting of a worm 65, a worm wheel 66, a toothed Wheel 67 and a pinion 68.

As the eccentric 61 is located below the center of gravity of the motor 11, edging or tilting of the latter cannot occur in this case. As the motor is positively raised and lowered by the eccentric 61, it is advisable in this form of construction to do away with any compensation of weight and to utilize the Weight of the motor to insure that the eccentric remains positively connected with the frame during the downward movement of the motor; additional springs 69 may however be provided for insuring the positive contact. j

To enable the vertical swinging movement of the motor to be cut out, so that the abrasive block will carry out only horizontal oscillations, as mentioned above, another eccentric 70 is provided, which can be manually operated by a lever 71; with the aid of this eccentric 70 the motor is raised from the carrier part 63.

The grinding head 23' is also in this case guided in horizontal direction by two parallel springs 24', which are secured on the motor frame by screws 72 and participate in the ver-tical oscillating movement. The movement of the eccentric 22', which is arranged on the high speed driving shaft 21' of the motor and balanced by an eccentric weight 73, is transmitted to the grinding head 23 by a ball bearing 74.

As the one sided stressing of the ball bearing 74 would result in heavy wear therein, it is advisable, in order to uniform or equilibrate the stresses on said ball bearing, to provide additional bearings 75, which as shown in Fig. 9, are rotatable about pins 80 in the housing 79. The ball bearing 74, wherein the eccentric 22 rotates, is arranged in the middle of the housing 79; the ball bearings 75 together with the housing 79 form a carriage which slides up and down between the lateral cheeks of the grinding head 23' and thereby transmits the components of the movements of the eccentric 22 to the grinding head 23.

A lubricant circulating pump in this form of construction of the machine is accommodated in one of the supports 14', in which the lower end of a piston 15 conv nected with the motor, is tted with the aid of a packing 76. The lubricant pump operates in other respects like that illustrated in Fig. 1.

In order to protect the frame against the vibrations, caused by the rapid horizontal oscillation of the grinding head, in spite of counterbalancing, intermediate bearings 77, 77a of oscillation absorbing material such as rubber, synthetic rubber are provided on the supports 14'.

A similar intermediate layer 78, 78a of oscillation absorbing material is tted under the eccentric 61 on the carrier part 63, and above the eccentric 70 in the base plate 13.

Details of construction of the work table 34' are shown in Figs. 7 and 8: The vertical adjustment is effected by a tooth rack 37', which is connected with the frame, and on which la pinion 36', connected with the table, rolls; this pinion is driven by hand wheel 38 through the intermediary of a worm 81 and a worm wheel 82; the spindle 83, on which the hand wheel and. worm are mounted, runs in ball bearings 84.

Various other structural changes and modifications may be conveniently made in abrading and finishing machines shown and described above, Without departing from the spirit and leading ideas of this invention.

What we claim is:`

1. ln a machine for abrading and finishing cutting tools of the type set forth, the combination with a base plate, of a frame mounted thereon, a work table, adjustably iixed at the front end of that frame, a motor vertically guided in said frame, means actuated by said motor for imparting to the latter an up and down movement in said frame, a grinding head carried by said motor and projecting over said work table, means operated by said motor for imparting horizontal oscillating motions to said grinding head, and a block of abrasive material carried by said grinding head and participating in its horizontal oscillating motions and in the vertical oscillatiug motions of the motor.

2. Abrading machine, as featured in claim 1, wherein an eccentric is carried on the front end of said motor, for imparting horizontal oscillating motions to said grinding head, and a second eccentric is carried on the rear end of said motor, and a connecting rod between said eccentric and the base plate, imparts a vertical oscillating motion to said motor and the grinding head.

3. Abrading machine, as featured in claim 1, wherein the motor isr resiliently supported on the base plate by springs tending to maintain the motor in raised position.

4. Abrading machine, as featured in claim 1, wherein the means for imparting the up and down and horizontal oscillations operate at different speeds, and wherein the up and down oscillations are under the control of a reduction gear in the motor.

5. Abrading machine, as featured in claim l, wherein means are provided for cutting out the up and down movement of the motor.

6. Abrading machine, as featured in claim 1, wherein means are provided for cutting out the up and down movement of the motor, comprising an ec entric, mounted in the machine frame under said motor, nd a hand lever connected to said eccentric, to raise and maintain the motor in raised position.

' 7. Abrading machine, as featured in claim l, wherein the block of abrasive material is provided with working surfaces at its front and upper side.

8. Abrading machine, as featured in claim 1, wherein the block of abrasive material is enclosed inv a frame of non-abrasive material, leaving an abrasive core exposed at the front surface of the block.

References Cited in the iile of this patent UNITED STATES PATENTS 

